/Engine/Source/Runtime/Engine/Classes/Curves/RichCurve.h
Add a new key to the curve with the supplied Time and Value. Returns the handle of the new key.
virtual [FKeyHandle](API\Runtime\Engine\Curves\FKeyHandle) AddKey ( float InTime, float InValue, const bool bUnwindRotation, [FKeyHandle](API\Runtime\Engine\Curves\FKeyHandle) KeyHandle )